The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
In a data center with large amount of storage space, a backplane is used to mount a number of storage drives, such as Disk Arrays, redundant array of independent disks (RAID) Subsystems, Small Computer System Interface (SCSI) and Fiber Channel (FC) Disk Array, and Switched Disk Array Servers. A host bus adapter (HBA) is used to facilitate the communication between a host computer and the backplane, and allows the host computer to monitor and manage the storage drives installed on the backplane. The backplane controller provides an operator with detailed information regarding the presence and status of mass storage devices, and provides facilities for generating visual indicators based upon backplane management data received from the HBA of the host computer. For instance, individual light-emitting diodes (“LEDs”) may be driven by a backplane controller for displaying information regarding the activity, failure, rebuild status, and other information for each of the mass storage devices connected to the backplane. In order to provide these indicators and other types of functionality, a backplane typically provides connections for multiple mass storage devices, such as hard disk drives.
A backplane is a circuit board with connectors and power circuitry into which storage drives are attached. They can have multiple slots, each of which can be populated with a storage drive. Typically the backplane is equipped with LEDs which by their color and activity indicate the status of the storage drives connected to the backplane. Typically, a storage drive's LED will emit a particular color or blink pattern to indicate its current status such as a storage drive is attached to the backplane, working, accessing data, or in fail state. The backplane also interfaces with an HBA and provides an interface through which the HBA may communicate with the mass storage devices. A backplane also may receive and transmit backplane management data to and from the HBA. Backplane management data is any data relating to the provision of backplane management services by a backplane.
Several different physical interfaces may be utilized to deliver backplane management data between an HBA and a backplane. For instance, some Serial Attached SCSI (“SAS”)-compatible HBAs are equipped with a serial general purpose input/output interface (“SGPIO”). Some Serial Advanced Technology Attachment (“SATA”)-compatible HBAs, on the other hand, utilize a control or management bus, such as the system management bus, to exchange backplane management data between the backplane and the HBA.
The particular protocol utilized to transfer backplane management data between the backplane and the HBA may also vary from vendor to vendor. However, the most popular protocols used in the backplane management are: the SCSI Enclosure Services (or SES) utilizing the system management bus (or I2C bus), and the SGPIO protocol utilizing an SGPIO interface to exchange backplane management information between the HBA and the backplane. For example, when one SGPIO channel with one SGPIO decoder is used in a backplane controller, the backplane controller monitors and manages up to four storage drives. If eight storage drives are to be managed by the backplane controller, another SGPIO sideband with another SGPIO controller is to be added. On the other hand, in order to reduce the hardware complexity and the cost of fabricating backplane controller chip, it is desirable to have a simplified backplane controller chip with reduced hardware, such as having one SGPIO controller for both SGPIO sidebands, and let firmware of the backplane controller to handle two SGPIO channels using one SGPIO decoder on a backplane controller.
Therefore, heretofore unaddressed needs still exist in the art to address the aforementioned deficiencies and inadequacies.